Time varying resistance in lumped parameter cardio-vascular system models

Lumped parameter cardio-vascular system models (LCVM) offer a simple and computationally inexpensive method of capturing the essential dynamics of the cardio-vascular system. Finite element methods (FEM) are the most commonly used alternative, offering accurate solutions at tht cost of extreme complexity and increased computational power and time requirements. Typical lumped parameter model equations governing arterial flow rate come in two forms either including or not including inertial effects. Resistance to blood flow in both cases is typically assumed to be Constant under varying flow velocity and acceleration, but resistance to flow varies with time for pulsating flows. The paper proposes a method to include the effect of time varying resislance on flow rate into lumped parameter models and describes the application to a single chamber model designed to simulate a single ventricular chamber.